Variety of prunus rootstock named &#39;Aprimed&#39;

ABSTRACT

A new and distinct hybrid plum-apricot plant used as a rootstock that exhibits root-knot nematode resistance, high tolerance to root asphyxia, and compatibility with apricot and plum varieties.

BOTANICAL CLASSIFICATION

(Prunus besseyi×P. armeniaca)×P. cerasifera

VARIETAL DENOMINATION

‘Aprimed’

BACKGROUND OF THE INVENTION

The present invention comprises a new and distinct cultivar of aplum-apricot hybrid (Prunus besseyi×P. armeniaca)×P. cerasifera used asa rootstock known by the varietal name ‘Aprimed’. The new variety wasdiscovered in Barcelona, Spain in 2000 as a result of a planned breedingprogram. The new variety is the result of a cross between an unknownclone of (P. besseyi×P. armeniaca) (female parent, unpatented) with anunknown clone of P. cerasifera (male parent, unpatented). The purpose ofthe breeding program was to develop a medium vigor rootstock that iswell adapted to Mediterranean conditions, compatible with apricotvarieties, and that has a high tolerance to poorly drained heavy soilsthat suffer from water logging conditions. The new variety exhibitssimilar good tolerance to calcareous soils, high resistance to root-knotnematodes, and resistance to several soil-borne fungi, especiallyRosellinia necatrix. The genotype has medium chilling requirements andgood productivity. It differs from both parents in its leaf shape andmedium vigor. Further, the clone does not emit suckers (root and crown)and tolerates water logging conditions better than its plum-apricotparents. Additionally, the new variety is similar to ‘Marianna 2624’(Prunus cerasifera×P. munsoniana) by exhibiting good compatibility withapricot varieties, root-knot nematode resistance, and good productivity.However, ‘Aprimed’ differs in vigor from ‘Marianna 2624’, bettertolerance to iron chlorosis, and absence of suckering. The new varietyhas been field tested and has been found to retain its distinctivecharacteristics and remain true to type through successive propagations.The following characteristics distinguish ‘Aprimed’ from other varietiesknown to the breeder:

1. Medium tree size with a capacity to control vigor;

2. High tolerance to root asphyxia;

3. Better tolerance to alkaline soils than most apricot and plumrootstocks;

4. Resistance to Rosellinia necatrix (soil-borne fungus);

5. Highly resistant to root-knot nematodes (Meloidogyne spp.);

6. Does not emit root, nor crown suckers;

7. Induces a sustained production from year to year; and

8. Medium chilling requirements within the range of 600 to 800 cu.

DESCRIPTION OF THE DRAWINGS

The accompanying photographic drawings illustrate the new variety withthe color being as nearly true as is possible with color illustrationsof this type:

FIG. 1 shows the flowers of the new variety;

FIG. 2 shows the stem and leaves of the new variety;

FIG. 3 shows upper and underside of leaves; and

FIG. 4 is a close-up view of stem and flower buds of the new variety.

DESCRIPTION OF THE PLANT

The following detailed description sets forth the characteristics of thenew cultivar. The data which defines these characteristics was collectedunder natural daylight on plants produced by asexual reproductions viain vitro propagation carried out in Barcelona, Spain in October of 2000.The plants were grown under normal field conditions with drip irrigationand in 40 liter containers. Color designations are presented withreference to the “Dictionary of Color” by A. Maerz and M. Rea Paul,Second Edition (1950).

-   Tree:    -   -   Age.—6 years.        -   Size.—2.1 meters tall.        -   Vigor.—Medium.        -   Density.—Medium.        -   Form.—Compact.        -   Production.—Medium to abundant.        -   Growth type.—Upright and spreading.        -   Bearing.—No fruit bearing.        -   Pathogen resistance.—Fungal disease: Phytophthora spp.            Insects: Unknown. Mites: Unknown. Viruses: Unknown. Other            diseases: Root-knot nematodes (Meloidogyne spp.).        -   Rootstock performance.—Root sprouts (suckering): Not            present. Anchorage: Good, with a fibrous root system.            Compatibility: Apricot and plum (European and Japanese            plum). Vigor: Medium (20-30% less than ‘Marianna 2624’).        -   Trunk.—Size: Perimeter of 30 cm. Surface texture: Fairly            smooth with longitudinal scarfskin and horizontally oriented            lenticels. Bark color: Plate 8, C 7. Lenticels: Length: 3 to            6 mm. Width: 1 to 1.5 mm. Color: Plate 15, C 2 (English            Grey, Crag). Density: Low.        -   Branches.—Diameter: Variable; from 0.5 cm to 1.3 cm in the            same season. Surface texture: Smooth in the current season.            Color: Plate 7, E 10 (Chestnut). Form: Circular in diameter.            Average angle: Acute. Bud arrangement: Helicoidal throughout            the branch. Lenticels: Length: 1 to 2 mm. in the first year            of growth and 2 to 5 mm. in the second year. Width: 0.5 to            1.5 mm. Shape: Younger tissue is initially rounded, turning            into elongated horizontally as the branches mature into the            season. Density: Medium and increasing as maturity advances.            Color: Plate 46, A 2 (Frost Grey, Chateau Grey).        -   Leaves.—Length: 7 to 9 cm. (end of season). Width: 4 to            5.5 cm. Form: Broadly elliptic. Texture: Smooth. Thickness:            Medium. Base: Acute. Apex: Acute to pointed. Margin: Between            crenate and serrate (mixed and not well defined).            Pubescence: Upper surface: Absent. Lower surface: Absent.            Color: Young leaves: Upper surface: Plate 23, C 12            (Brunswick Green). Lower surface: Plate 23, A 5. Mature            leaves: Upper surface: Plate 23, E 7. Lower surface: Plate            22, B 6 (Palmetto). Petiole: Shape: Straight with central            groove along the upper side with 2 small nectaries at the            base of the leaf. Length: 19 to 22 mm. Diameter: 1.5 to            2 mm. Color: Plate 7, J 9 (Tanagra, Castilian Brown). Veins:            Venation type: Tree-type disposition. Color: Upper surface:            Plate 7, J 9 (Tanagra, Castilian Brown) changing gradually            to Plate 14, L 1 (Palm Leaf). Lower surface: Plate 7, H 9            (Live Brown, Autumn Oak) changing gradually to light green            tones Plate 21, C 2 (Tea Green).        -   Flower buds.—Pedicel: Length: 4 to 8 mm. Diameter: 0.8 to            1 mm. Color: Plate 44, B 3 (Irisglow). Bud: Length: 4 to            5 mm. Width: 2 to 4 mm. Shape: Rounded to ovoid. Color:            Plate 6, K 8 (Saraband).        -   Flowers.—Bloom timing: End of February to the first week of            March in Barcelona, Spain. Blooming period: 10 to 12 days.            Pollination requirements: None. Number of flowers per            raceme: Normally two present. Fragrance: Not perceptible.            Petals: Number: 5. Length: 8 to 10 mm. Width: 7 to 9 mm.            Shape: Rounded. Aspect: Cupped upwards and inwards. Margin:            Undulate. Texture and appearance: Smooth. Color: When            opening: Upper surface: Plate 1, A 1. Lower surface: Plate            1, B 1. Fully opened: Upper surface: Plate 1, A 1. Lower            surface: Plate 1, A 1. Sepals: Shape: Rounded. Margin:            Smooth. Texture: Pubescence present. Length: 3 to 4 mm.            Width: 2 to 3 mm. Color: Upper surface: Plate 6, L 8 (Dark            Cardinal). Lower surface: Plate 14, L 1 (Palm Leaf).            Stamens: Number (per flower): 24 to 30. Filament length: 8            to 9 mm. Anthers: Shape: Kidney-shaped. Length: 1 to 1.5 mm.            Color: Plate 12, J 5 (Light Stone). Pollen: Color: Plate 11,            J 4 (Mustard). Amount (generally): Abundant. Pistils:            Length: 12 to 14 mm. Style: Length: 10 to 11 mm. Color:            Plate 12, F 1. Stigma: Shape: Rounded. Color: Plate 12, L 1            (Oil Y.).        -   Fruit.—None produced.        -   Use.—As a medium vigor rootstock that is highly compatible            with apricots, but can also be used for plums.        -   Tree winter hardiness.—Hardy (under the conditions in            Spain).        -   Bud winter hardiness.—High.        -   Tolerance to root asphyxia.—Highly tolerant.        -   Tolerance to iron chlorosis.—Tolerant.        -   Drought tolerance.—Moderately tolerant.        -   Disease resistance.—Highly resistant to root-knot nematodes.

I claim:
 1. A new and distinct variety of hybrid plum-apricot plant, asillustrated and described herein.